LP gas or LPG is an abbreviation for liquefied petroleum gas. Like all fossil fuels, it is a non-renewable source of energy. It is extracted from crude oil and natural gas. The main composition of LPG is hydrocarbons containing three or four carbon atoms. The typical components of LPG are propane (C3H8) and butane (C4H10). Small concentrations of other hydrocarbons may also be present. Depending on the source of the LPG and how it has been produced, components other than hydrocarbons may also be present.
LPG is a gas at atmospheric pressure and normal ambient temperatures, but it can be liquefied when moderate pressure is applied or when the temperature is sufficiently reduced. It can be easily condensed, packaged, stored and utilized, which makes it an ideal energy source for a wide range of applications. Normally, the gas is stored in liquid form under pressure in a steel container, cylinder or tank. The pressure inside the container will depend on the type of LPG (Commercial butane or commercial propane) and the outside temperature.
In the LPG industry, a common means of transferring the liquid product from its storage container to a combustion device for example, other than metallic pipe, involves the use of high- and low-pressure flexible hoses. These hoses are fabricated to meet applicable regulations, including a design pressure of 350 psi, a safety factor of 5 to 1, and “be fabricated of materials that are resistant to the action of LP gas both as liquid and vapor.” See National Fire Protection Association (“NFPA”) 58 2-4.6.1
However, the term “resistant” is not defined in NFPA, but does not necessarily mean impervious. Extractable contaminants which have been detected in gas exiting through these hoses includes, but are not limited to, phenyl beta-naphthylamine, phthalates (e.g., dibutylphthalate, diisooctylphthalate, dioctyl/nonyl phthalate isomer, di-nonylphthalate isomer), adipates (e.g., dioctyladipate), sebacates (e.g., dibutyl sebacates), lower molecular weight alkanes (e.g., C12-C20 alkanes) and sulfur. Phenyl beta naphthylamine is a well-known antioxidant used in compounding rubber, phthalates are common plasticizers, and elemental sulfur is a rubber-vulcanizing agent. When these contaminants exceed their solubility limits, as occurs particularly at the atomizer of combustion devices, such as portable heaters, or are deposited within the small diameter tubing leading to the atomizer, the resultant oily residue leads to clogging in both the tubing and the nozzle tip.
It has even been determined that the varying compositions of LP gas can influence the amount of plasticizer extracted from the hoses. Butane has been found to extract less plasticizer than propane, and propane extracted less than propylene. The extraction of all constituents increases with temperature. Fuel quality standard HD-5 limits the amount of propylene to 5% and butane to 2.5% by volume. However, commercial grade product is defined as “predominantly propane and/or propylene” with a 2.5% limit on butane. The different grades of product are not normally separated in the broad distribution system in North America.
It is an aspect of the present invention to provide a separation device which effectively removes extractable constituents from LPG hoses prior to the LPG nozzle tip before entry into the combustion chamber. In one embodiment of this invention, this removal is effected by the incorporation of a downwardly and upwardly fingered impingement region or surface which selectively promotes gas flow through the device yet traps undesirable lower molecular weight hydrocarbons and oligomers which form viscous oils which often solidify after condensing from the gas, thereby preventing clogging of small diameter passageways which lead up to nozzle adjacent the combustion chambers of heating devices in particular.
It is another aspect of this invention to provide an inexpensive separation device which effectively removes extractable constituents from LPG hoses for at least one entire heating season.
To the accomplishment of the foregoing and related ends the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.